In 1983, she returned to private practice as a member of the firm of Sinkler, Gibbs & Simons of Charleston and Columbia, South Carolina.
[1] In Parker v. District of Columbia (2007) Henderson authored a dissent in which she wrote "the right of the people to keep and bear arms relates to those Militia whose continued vitality is required to safeguard the individual States.
[6][7] The case was reportedly the first federal appeals court decision involving the treatment of terrorism suspects in the wake of the September 11 attacks.
[12][13] In October 2017, Henderson dissented in the en banc-stage of Azar v. Garza, arguing that an undocumented immigrant is not a "person" under the United States Constitution and so does not have rights under the Due Process Clause.
[21] On November 30, 2021, Henderson authored a unanimous ruling requiring the DOJ hand over more of the Mueller report, citing the Freedom of Information Act.
Henderson responded in a statement: "I give equal treatment and consideration to all applicants and hire law clerks based only on their credentials.